Apparatus for measuring angular gamma-gamma correlations in specimens with temperature of 1. 5-300/sup 0/K

Apparatus for measuring angular gamma-gamma correlations perturbed by a magnetic field of 2.0 T in specimens with temperatures of 1.5-300 degrees K is described. It is established that the strength of the hyperfine magnetic field for /sup 154/Gd nuclei in an Fe matrix at 4.2 degrees K is 36.1 + or - 0.5 T. Investigation of angular-correlation perturbation (ACP) of cascade gamma quanta in the study of radioactive nuclei under the influence of external electromagnetic fields permits determination of the magnetic dipole and electric quadrupole moments of the excited states of atomic nuclei. In addition, the ACP method is used to study internal electromagnetic fields that act on nuclei in ferromagnetic or paramagnetic materials as well as the dependence of these fields on the specimen temperature.